-LRB- CNN -RRB- -- Be bold ! Think big ! Barack Obama wants to do just that . An $ 800 billion economic stimulus plan . Three million jobs . Health care reform . A restructured automobile industry .

Obama 's popularity with voters will win him influence with political opponents .

Obama won the biggest Democratic majority for president in 44 years . His party made big gains in Congress . Democrats now have a majority of nearly 60 percent in both the House and Senate . President Obama 's got a mandate . And a majority . What 's to stop him ?

Just this : the U.S. system of government . It is set up to make it difficult to get things done .

The Constitution was written 222 years ago by men who did n't trust government . They had just waged a revolution against a king . To the founders of the American republic , strong government meant despotism .

So they set up a system with an elaborate separation of powers . The idea was to ensure weak government .

The dirty little secret of American government is that it was designed not to work very well .

As president after president has discovered , there are innumerable ways opponents can stop measures from getting passed , even if the president 's party holds a majority in Congress .

The Senate has its own rule that 's not in the Constitution requiring a super-majority of 60 Senate votes to control the agenda .

A minority of 41 senators can `` filibuster '' a measure and prevent it from coming up for a vote . How many votes will Republicans have in the Senate ? 41 or 42 , depending on the outcome in Minnesota where ballots are still being counted .

Presidents often have problems holding their own party together . That 's because members of Congress are elected by local constituencies and they are expected to represent local interests .

American politicians are independent political entrepreneurs . They are not foot-soldiers of a party .

When Bill Clinton first became president , he had a solid Democratic majority in Congress . But he could not get his health care reform plan passed .

After an intense advertising campaign by opponents , many Americans were worried that the Clintons were planning a government takeover of the health care system . The Clinton plan failed , and within two years , Democrats lost their majority in Congress .

One-party control did n't work any better for George W. Bush . Bush had trouble getting what he wanted -- notably , immigration reform -- from a Republican Congress . Republicans lost their majority in Congress in 2006 .

But here 's another dirty little secret of American government : it often does work . Very well in fact .

Under the right conditions , barriers fall away and things get done , sometimes with amazing speed and efficiency .

What are the right conditions ? An overwhelming sense of public urgency . That sense of urgency certainly existed after 9/11 , when Congress quickly passed the Patriot Act .

Getting anything big done in American government requires a sense of crisis . That 's why politicians in the U.S. are always declaring crises -- a drug crisis , an education crisis , an environmental crisis . Or they 're trying to rally the country to fight a war on something -- a war on poverty , a war on crime .

If the public urgency is not authentic , however , opponents wo n't have much trouble stopping things from happening .

Obama certainly takes office at a time of crisis , just as Abraham Lincoln and Franklin D. Roosevelt did .

Like them , he has the opportunity to transform American government . Members of Congress who try to block President Obama 's program may find themselves in political trouble .

Because there is yet another dirty little secret of American government : the United States is the most populist democracy in the world .

Here , the people rule .

When the people want something , they will get it , whether it 's the death penalty or gun rights or lower taxes .

Why does n't the United States have a metric system or dollar coins like other countries ? Because the people wo n't use them .

Obama 's popularity is soaring right now . When a president is popular , he has clout .

Everyone wants to be on his side , even members of the opposition party . They 're in business for themselves , and supporting a popular president is good for business . Standing in his way could drive them out of business .

American government is not an efficient , well-oiled machine . It was never designed to be . It has to be lubricated by public pressure .

If the people are shouting `` Do something ! '' -- as they are right now -- then something will happen . Even if it means a lot more spending and a lot more government .

The people reserve one key right : they will let the government know , rather quickly , whether or not it 's working .

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Three secrets behind the way U.S. government works

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It was designed to ensure weak government

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In times of crisis usual barriers fall away

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If voters want something done , it will get done somehow